The inventive concepts disclosed herein relate generally to actuator systems, and more specifically, to systems and methods for actively monitoring the health of a no back brake device for a stabilizer actuator system.
Actuator systems such as horizontal stabilizer trim actuators may use no back brake devices to avoid unwanted movement of the actuator. In some systems, ballscrew assemblies are employed where a horizontal stabilizer is coupled to a ball nut on the ballscrew. The no back brake device avoids undesirable movement of the horizontal stabilizer by resisting movement of the ballscrew upon which the ball nut, and in turn the horizontal stabilizer, move.
Aircraft typically utilize horizontal stabilizers that pivot relative to the fuselage of the aircraft. The horizontal stabilizer is adjusted, or trimmed, by way of an actuator. Some actuators include a ballscrew that extends from a primary gimbal on the aircraft fuselage to a ball nut coupled to the horizontal stabilizer. Rotation of the ballscrew causes a corresponding upward or downward movement of the ball nut along the ballscrew, thereby enabling upward and downward adjustment of the horizontal stabilizer. The ballscrew is typically rotated by way of a motor (e.g., an electric or hydraulic motor), which may be used to position the horizontal stabilizer in a desired position during take-off, cruising, landing, etc.
During flight, aerodynamic loads act upon the horizontal stabilizer, and these loads are transmitted to the ballscrew assembly. To avoid undesirable movement of the ballscrew, a brake device, referred herein to as a “no back brake” device, is used. A typical no back brake device resists movement of the ballscrew assembly arising from aerodynamic loads in both an upward and downward direction.